Does anyone have advice on power cables?

I am looking to upgrade the power cables for my home theater and was wondering if anyone has good advice as to where to start. I currently have a Cambridge Audio Azur 640R, Dynaudio Audience 82 front, 52 sides, 122 back and 122c center with an Earthquake Supernova sub. The components are ran through a Monster Reference 3500 mkII and a Monster UPS. The current power cables that I am using are the stock cables on the receiver and sub, but have Monster cable 300 power cables on the power conditioner and ups. I am using Monster m2.2s speaker cables for the fronts and center and XPHP CI in-wall for the sides and back. I was considering trying the Anticables for the front and center, but that is for another thread.

I guess my question is should I upgrade all power cables to see a difference, or is it most important to upgrade the receiver, or the power conditioner, or the ups? And does anyone have advice on good power cables that won't break the bank. I don't want to put a $1000 Cardas Golden reference cable on a $1500 receiver. Any help would be greatly appreciated. One other thing, I might be upgrading to a Marantz processor with an 8 channel amp setup, not that that impacts my question here.